PROJECT SUMMARY/ABSTRACT?Cell and Tissue Imaging Shared Resource The primary goal of the Cell and Tissue Imaging Shared Resource (CTISR) is to make state-of-the-art technology and analysis tools for imaging cells and tissues available to SJCCC investigators and trainees. The CTISR consists of 2 divisions: Light Microscopy, led by Dr. Victoria Frohlich, and Electron Microscopy, led by Sharon Frase. Together, Frohlich and Frase have more than 90 years of experience in scientific imaging. The CTISR is further staffed by 8 experienced imaging scientists who assist with acquisition, analysis, quantification, presentation, and publication of imaging data. The CTISR staff collaborates with SJCCC members prior to beginning a project to provide guidance on experimental design, appropriate imaging modalities, sample preparation, and data-analysis options. The degree of direct staff involvement in specimen preparation, imaging, and analysis is determined. The CTISR also provides user training when applicable. During the reporting period (FY2017), CTISR-LM conducted 60 consultations with 40 SJCCC labs and trained 95 new instrument users. Selected accomplishments in the current reporting period include a collaboration with Drs. Tanja Mittag (CBP), Richard Kriwacki (CBP), and J. Paul Taylor (NBTP) to visualize and characterize the role of liquid?liquid phase transition in the formation and maintenance of membraneless organelles. This work is now being expanded in an SJCCC-funded inter-center Collaborative as described in the Strategic Plan section of the Director's Overview. Additionally, CTISR staff assisted Dr. Charles Mullighan (HMP Co-Leader) to document, by confocal and in situ multiphoton imaging, the perturbations and stem cell-like phenotype caused by mutated IKZF1, a hallmark of high-risk acute lymphoblastic leukemia (ALL) and to detect the reversal by treatment with retinoids. As a result, clinical evaluation of retinoids for IKZF1-altered Philadelphia chromosome-positive ALL is being pursued (Churchman et al., Cancer Cell, 2015). During the current project period, CTISR contributed to 159 publications authored by SJCCC members. Of these, 40 (25%) were interprogrammatic and 34 (21%) were intraprogrammatic. CTISR staff were co-authors of 24 (15%) of the publications, signifying the value of their expertise to the research presented. CTISR resources contributed to 70 publications in high-impact journals (impact factor >10) such as Cell, Nature, and Nature Genetics. Over the next five years, the CTISR plans to continuously expand and evolve services?including education and training programs?and technologies such as Lattice Lightsheet and virtual reality visualization, enabling SJCCC members to effectively pursue emerging directions in cancer research. CTISR staff will continue to educate SJCCC members on available methods to use correlative microscopy (CLEM) approaches to enhance cancer research. By leveraging and incorporating high-performance computing resources, the CTISR will augment statistical and analytical tools and assist SJCCC members in applying these tools to their research.